Fire extinguishing apparatus



June 11, 1968 F. A. MOLGANO, JR 3,387,662

F IRE EXT INGUI SHING APPARATUS Filed Aug. 31, 1966 2 Sheets-Sheet 1 20:: Frank A 114 02 qcduo J INVENTOR Frank hM olyanqfi:

RNEYS June 11, 1968 F. A. MOLGANO, JR 3,387,662

FIRE EXTINGUISHING APPARATUS 2 Sheets-Sheet 2 United States This invention relates to fire extinguishing apparatus and systems for engine compartments, burners, electrical equipment and other enclosed or semi-closed areas and more particularly to a compact extinguishing system with a positive release and distribution of fire extinguishing agent upon energization of the system.

Prior art fire extinguishing systems and especially those for automobiles have had a number of drawbacks. For example, systems which use carbon dioxide as the fire extinguishing agent require extremely high pressures in the carbon dioxidecylinder and a great amount of carbon dioxide in a large bulky tank or container. Other prior art systems employing dry chemicals such as bicarbonate of soda have inherent disadvantages in the distribution of the fire extinguishing agent and the resulting contamination by the agent residue if a minor fire occurs.

Among the prior art fire extinguishing systems for motor vehicles are US. Patents 2,596,761, 2,841,228, 2,380,966, and 2,338,440. The systems disclosed in these prior art patents also have problems of reliability as to valve systems and controls in the system which can corrode after long periods of non-use or jam in operation. Further, for those systems which employ thermally fusible fire detection apparatus there is required an inordinate number of such detectors for proper detection coverage in the protected area.

Even more complicated prior art fire extinguishing systems have been devised for aircraft such as disclosed in U.S. Patent Nos. 2,551,752, 2,537,074, and 2,815,819. As disclosed in U.S. Patent No. 2,537,074 a frangible disk may be employed to retain the fire extinguishing agent with the disk being shattered by a cartridge or plunger to release the fire extinguishing agent. Such a system, however, requires strainers and other precautions in the system to prevent pieces of the frangible disk from plugging the conduits for the fire extinguishing liquid. This problem has been further encountered in systems employing a thin metal seal which is pierced to release the fire extinguishing agent. In such systems one or more pieces of metal may clog or impede the fiow of liquid in the fire extinguishing lines and/ or valves, or the piercing pin itself may be plugged by such a piece of the seal and interfere with the flow of fire extinguishing liquid from the reservoir.

Further, because of the pressure in the container for the fire extinguishing liquid the piercing pin may be driven from the pierced seal and impede the flow of fire extinguishing agent or to permit some degree of reclosure by the cut portion of the seal.

Accordingly, it is an object of this invention to provide a fire extinguishing system which is compact and reliable in operation.

Another object of the invention is to provide an apparatus for the above system which is reliable in operation and inexpensive to manufacture and maintain.

A further object of the invention is to provide a fire extinguishing system of the above character employing a fire extinguishing agent maintained under pressure as a liquid having a puncturable seal for release of said agent.

Another object of the invention is to provide a fire extinguishing system of the above character wherein a puncturing apparatus for release of the fire extinguishing agent is positive in its action and cannot be blocked by pieces of the seal or other foreign matter.

A further object or" the invention is to provide a fire exent O" 3,387,552 Patented June 11, 1958 "ice tinguishing system of the above character wherein the fire extinguishing agent is halogenated methane or ethane.

Another object of the invention is to provide a fire extinguishing sys cm of the above character wherein the fire extinguishing agent is piped as a liquid to one or more discharge points having expansion nozzles for a change of state from a liquid to a gas of the agent and for directing the agent into the fire protected area.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a schematic perspective view of my fire extinguishing system employed in the engine compartment of an automobile.

FIGURE 2 is a side sectional view of a discharge nozzle of my fire extinguishing system taken along lines 2-2 of FIGURE 1.

FIGURE 3 is an end view of a discharge nozzle of the fire extinguishing system of my invention.

FIGURE 4 is a side view in partial section of the release valve assembly and a schematic representation of the fire detector circuit of my system.

FIGURE 5 is an end view in partial section taken along lines 5-5 of FIGURE 4.

FIGURE 6 is an enlarged partial sectional view of the puncturing pin after piercing the container seal.

FIGURE 7 is a partial top sectional view taken along lines 66 of FIGURE 5.

Referring now to FIGURE 1, the system in general comprises a pressurized container 10 for a fire extinguishing agent such as a halogenated methane or ethane which is connected to a release valve assembly 12 which may be secured to the fire wall 14 of an automobile. The container and/or valve assembly may also be located in the auto trunk. One or more discharges lines 1618 are in close communication with the release valve assembly 12 and with discharge nozzles 20a, b and c which are directed for discharging the fire extinguishing agent around an automobile engine generally designated at 22. One or more discharge nozzles may also be located in the passenger compartment of an automobile. Fire detection assembly 2-4 is secured in an M-shaped configuration to the automobile hood 26 over the engine compartment and is connected into a fire detector circuit foroperating the release valve assembly in the event of a fire as is more fully explained hereinafter. Upon detection of a fire in the engine compartment the fire detector assembly 24 causes the circuit to actuate the release valve assembly 12 to flood the engine compartment with a fire extinguishing gas.

The preferred fire extinguishing agent is bromotrifluoromethane which is a liquid under pressure in the container, but when mixed with air and under-reduced pressure becomes a gas with excellent fire-quenching properties. The preferred bromotrifiuoromethane is sold under the trademark designation Freon FE 1301 by the E. I. du Pont Company. Other halogenated methanes may also be used in the system such as dibromodifiuorornethane and bromochloromethane. It should also be understood that such compounds as carbontetrachloride have well-known disadvantages which would militate against their use except in very limited circumstances. The preferred bromotrifiuoromethane is considerably less toxic than homologous halogenated methanes as well as having superior fire quenching characteristics. I-Ialogenated ethanes such as dibromotetraiiluoroethane may also be used, but have not been found to be as eflective as bromotrifiuorornethane. Accordingly, the designation of halogenated methane or ethane broadly defines the class of fire extinguishing agents which may be used in the system.

Referring now to FIGURES 4, 5 and 6, the apparatus and system of the invention will be explained more fully.

As shown in FIGURES 4, 5, 6 and 7, the pressurized container 10 is a steel cylinder, for example, containing from 1 /2 pounds to 2% basic pounds of fire extinguishing agent under a pressure of from 200 to 400 psi. and having a threaded neck for engagement with the release valve assembly. The pressurized contents are held in the container by a puncturable seal 28 of thin steel secured in the bottle neck. The threaded neck portion 27 fits into a threaded connection 30 of the plenum chamber 31 which is secured to the release valve assembly base plate 32 and which opens into a T-connection 34 for distribution through conduits 16, 18.

Secured on base plate 32 of the release valve assembly 12 is a striker assembly 36 comprising a striker 38 pivotally mounted at 40 on a pair of spaced supports 42 which are secured to base plate 32. A spring 44 urges the striker 38 downwardly toward the puncture pin 46 to be released by latch 48.

The striker 38 has an open center portion so that the spring 44 can pass therethrough as shown in FIGURE 5 to urge the striker toward the puncture pin when released. The spring 44 exerts a force on the striker of at least 35 pounds. Thus the spring 44 is strong enough to insure puncturing of the seal 28 by pin 46 and to further assure that the puncture pin 46 will be held in its down position as shown by dashed lines in FIGURE 4 while the contents of container 10 are being discharged therethrough. If the puncture pin 46 is forced upwardly by the pressure of the contents of container 18, the flow of fire extinguishing agent may be impeded or blockage of the pierced seal may occur such as by the cut tang portion 28a (FIGURE 6).

Latch 48 is pivotally supported at 50 on support 52 secured to the base 32 of the assembly, latch 48 being connected by a link 54 to the rod 56 which is vertically operated by solenoid 58 and which is urged to its upper position by a spring 60 bearing against retainer flange 62. Latch 48 may also be operated manually by a cable wire 64 which is secured to bracket assembly 66 Thus the latch 48 may be released from inside the automobile by manual means to override the circuit of solenoid 58 or to actuate the fire extinguishing system in the event that the electrical circuit or solenoid 58 are inoperative.

The puncture pin 46 is slidably mounted in an opening 66 in base 32 between upper and lower retaining flanges 68 and 78 respectively to position the puncture pin over the seal member 28 of the container 10'.

As shown in FIGURE 6 the lower portion of puncture pin 46 has a sharp bevelled end 46a for piercing and cutting the sealing member 28 when driven downwardly by the striker 38, except for a relieved portion 46b which does not perform a cutting action when the puncture pin is driven downwardly into the seal 28. As shown in FIG- URES 6 and 7, the relieved portion 46b prevents the cutting of a complete circular segment of the seal 28 and results in a driving down of a roughly circular portion or tang 28a which is held away from the open bottom of the puncture pin by the vertical segment of portion 46b which enters the seal. Thus the tang 28a will not become a loose piece of material in the system capable of blocking the valve assembly or the conduits.

The puncture pin 46 is provided with outlet ports 46c, d and e for the release of the fire extinguishing agent when the puncture pin penetrates the seal element 2.8 and the pin is held by striker 38 in the position shown in FIGURES 6 and 7.- .As shown by the arrows in FIG- URE 7, the tire extinguishing agent will escape upwardly through the puncture pin and out all of these exit ports into plenum chamber 31. Port 46e is positioned to straddle the puncturable seal member 28 when the striker 38 drives the puncture pin 46 to the limit of its downward travel as determined by upper flange 68. The pressure of striker spring 44 maintains the puncture pin in its downward position as shown in dashed lines in FIGURE 4 to maintain port 462 astraddle the seal 28. Thus, as shown in FIGURE 6 in this position, the fire extinguishing agent will flow from the interior of puncture pin 46 through port 46e and may also flow into and through port 46c from the exterior of the puncture pin in the event that the interior of the puncture pin should become plugged because of foreign material from the container or by corrosion. The providing of a multiple escape path both through and around the puncture pin eliminates the problems of puncture pin blockage and greatly increases the reliability of the release valve assembly.

As shown in FIGURES 2 and 3, the discharge nozzles 28a, [2 and c comprise a threaded coupling assembly '72 for securing of the nozzle to the discharge line 16. The discharge nozzle has an outwardly flaring horn member 74 having air inlet ports 76 near its connected end around the discharge opening 78 of conduit 16. Spaced from the ports 76 and centered within the nozzle horn 74 is a short cylindrical mixing tube 80 which is secured to the horn by positioning members 82.

The fire extinguishing agent is in liquid form under pressure as it comes from the container 10 and as it is released through opening 78 of conduit 16. As the liquid passes into the horn 74 it is mixed by the mixing tube 80 with air drawn in through ports 76. The decrease in pressure along with the mixing effect results in a rapid change in the state of the fire extinguishing agent from a liquid to a gas in the nozzle horn. As the gas emanates from the nozzle horn, it flows from the horn and rapidly floods and extinguishes the fire.

Referring now to FIGURE 4, the release valve assembly solenoid 58 is operated by the car battery 84 or other source of electrical energy by a closing of the circuit in the detector assembly 24- through Wires 86, 88. Detector assembly 24 is comprised of a pair of spring steel wires 24a and 24b which are covered with electrical insulating material which is melted or decomposed at a predetermined temperature to cause the wires 24a, 24b to come together and complete the electrical circuit. Such fire detection wire assemblies are commercially available and are greatly preferred for use in my fire extenguishing system. Thus, as seen in FIGURE 1, a fire occurring in the engine compartment of an automobile will cause a melting or deterioration of the insulating material around the wires 24a, 24b at any point along the M-shaped deployment of the wire to complete the circuit from the battery 84 to the solenoid 58. Upon energization of the solenoid 58, the plunger 56 is pulled downwardly actuating latch 48 to release the striker 38 which is driven by its spring 44 onto the top flange 68 of puncture pin 46 to pierce the container seal 28 and release the fire extinguishing agent.

A fuse 96 may be interposed in the solenoid circuitry as shown in FIGURE 4 to open the circuit from battery 84 to the solenoid 58 after actuation of the solenoid. In some applications a switch assembly 92 having a toggle 94- may be positioned for actuation by striker 38 to the dashed line position shown in FIGURE 4 to open the solenoid circuit in place of the fuse and also to open or close other circuits to initiate signal lights, alarms, etc.

Although the fire extinguishing system and apparatus shown herein is applicable to the extinguishing of automobile engine fires, it should be understood that the systern may be employed in and around other types of engines such as those for boats or airplanes, for oil burners and furnaces, electrical motors or switching equipment and other closed or semi-closed areas where such an automatic fire extinguishing apparatus may be required or desirable.

It will thus be seen that objects set forth above, among those made apparent from the preceding description, a e efiiciently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A fire extinguishing system for protecting a defined area, comprising in combination:

(A) a pressurized container of fire extinguishing agent with a puncturable seal at its securable end,

(B) a release valve assembly comprising (1) a puncturing pin disposed above said container seal,

(a) said puncturing pin having means limiting its travel through said seal,

(b) and having means forming an opening from the lower interior of said pin to the pin exterior at a point outside said container when said pin is at its limit of travel into said container seal,

(2) a pivotally mounted striker (a) having spring means urging said striker toward the top of said puncturing pin,

(3) a latch for holding said striker in a raised position, (4) a latch release solenoid (2.) having a link connected to said latch for releasing said latch upon energization,

(C) means forming a plenum chamber around the lower portion of said puncture pin and securable to said container adjacent said container seal,

(D) at least one fire extinguishing nozzle in the fire protected area and connected in fluid communication with said planum chamber, and

(E) a fire detector in the fire protected area connected between said source of electrical power and said latch release solenoid for energizing said solenoid for release of said striker when a fire occurs in the protected area.

2. A fire extinguishing system as defined in claim 1 wherein said puncture pin is slidably mounted, provided with upper and lower limiting stops and is tubular with at least one primary outlet port and at least one secondary outlet port, said primary outlet port being spaced from said seal in said plenum chamber and said secondary outlet port straddles said seal when said pin is at its lowermost position.

3. A fire extinguishing system as defined in claim 1 wherein said puncture pin has a cutting periphery around its lower end except for a relatively small non-cutting area whereby the cut portion of said seal is retained as a part of said seal and is forced into said container by the entry of said pin.

4. A fire extinguishing system as defined in claim 1 wherein said fire detector comprises a pair of resilient wires covered by heat degradable insulation, said wires being urged toward one another, one of said wires being connected to said solenoid and the other of said wires to a source of electrical power, whereby degradation of said wire insulation at a predetermined temperature permits electrical contact between said wire pair to energize said solenoid.

5. A fire extinguishing system as defined in claim 1 wherein said nozzle is in the shape of an outwardly flaring horn and is provided with means forming at least one air inlet port adjacent the smaller end of said horn and a tubular sleeve is positioned within said horn toward the larger end thereof, said plenum chamber being connected in fluid communication with the small end of said horn whereby said fire extinguishing agent enters said horn as a liquid and undergoes a change of state to a gas as it is mixed with air in said horn.

6. A fire extinguishing system as defined in claim 1 wherein there is provided means interposed in the electrical circuit between said solenoid and a source of electrical power for de-energizing said solenoid after said striker latch is released.

7. A fire extinguishing system as defined in claim 1 wherein said striker spring means bears on said striker with sutficient force to prevent said puncture pin from being driven from said seal upon release of said container contents through said puncture pin.

8. A fire extinguishing system as defined n claim 1 wherein there are electrical switch means secured adjacent the path of movement of said striker when it is released, said switch means having an operating member in the path of said striker and connected to operation indicia when said switch is operated by said striker to indicate operation of said system.

9. A fire extinguishing system as defined in claim 1 wherein said fire extinguishing agent is a halogenated alkane taken from the group consisting of methane and ethane, and is under sufiicient pressure in said container to maintain it as a liquid until released through said nozzle. I

10. A fire extinguishing system as defined in claim 9 wherein the halogens of said halogenated alkane are taken from the group consisting of bromine and fluorine.

References Cited UNITED STATES PATENTS 1,837,619 12/1931 Heckert 169-26 1,838,655 12/1931 Bronander 169-26 X 1,881,608 10/1932 Hunter 16926 2,127,395 8/1938 Evans 16926 2,547,018 4/ 1951 Kucher. 2,585,039 2/1952 Rooke 16926 X 3,063,258 11/ 1962 Szachnitowski. 3,091,365 5/1963 Horner et a1. 16926 X FOREIGN PATENTS 267,542 6/1927 Great Britain. 230,812 4/ 1944 Switzerland.

M. HENSON WOOD, JR., Primary Examiner.

VAN C. WILKS, Assistant Examiner. 

1. A FIRE EXTINGUISHING SYSTEM FOR PROTECTING A DEFINED AREA, COMPRISING IN COMBINATION: (A) A PRESSURIZED CONTAINER OF FIRE EXTINGUISHING AGENT WITH A PUNCTURABLE SEAL AT ITS SECURABLE END, (B) A RELEASE VALVE ASSEMBLY COMPRISING (1) A PUNCTURING PIN DISPOSED ABOVE SAID CONTAINER SEAL, (A) SAID PUNCTURING PIN HAVING MEANS LIMITING ITS TRAVEL THROUGH SAID SEAL, (B) AND HAVING MEANS FORMING AN OPENING FROM THE LOWER INTERIOR OF SAID PIN TO THE PIN EXTERIOR AT A POINT OUTSIDE SAID CONTAINER WHEN SAID PIN IS AT ITS LIMIT OF TRAVEL INTO SAID CONTAINER SEAL, (2) A PIVOTALLY MOUNTED STRIKER (A) HAVING SPRING MEANS URGING SAID STRIKER TOWARD THE TOP OF SAID PUNCTURING PIN, (3) A LATCH FOR HOLDING SAID STRIKER IN A RAISED POSITION, 